Collision handling between sTTI and TTI transmissions

ABSTRACT

For collision handling between shortened Transmission Time Interval (sTTI) and Transmission Time Interval (TTI) transmissions, a method determines a collision between user equipment (UE) uplink transmission resources in a first TTI 16 of a first TTI length and uplink transmission resources in a second TTI 16 of a second TTI length. The method further transmits a first uplink data transmission block (TB) in the first TTI and a second uplink data TB in the second TTI. The method interrupts the transmission of the first uplink data TB before transmission of the second uplink data TB. The method receives an indication that indicates whether to resume transmission of the first uplink data TB. The method determines to resume the transmission of the first uplink TB based on the indication.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/502,510 entitled “METHODS OF COLLISION HANDLING BETWEEN STTI andTTI TRANSMISSIONS” and filed on May 5, 2018 for Hossein Bagheri, whichis incorporated herein by reference.

FIELD

The subject matter disclosed herein relates to collision handling andmore particularly relates to collision handling between shortenedTransmission Time Interval (sTTI) and Transmission Time Interval (TTI)transmissions.

BACKGROUND Description of the Related Art

Long Term Evolution sTTI and TTI transmissions may collide.

BRIEF SUMMARY

A method for collision handling between sTTI and TTI transmissions isdisclosed.

The method determines a collision between user equipment (UE) uplinktransmission resources in a first TTI of a first TTI length and uplinktransmission resources in a second TTI of a second TTI length. Themethod further transmits a first uplink data transmission block (TB) inthe first TTI. The method transmits a second uplink data TB in thesecond TTI. The method interrupts the transmission of the first uplinkdata TB before transmission of the second uplink data TB. The methodreceives an indication that indicates whether to resume transmission ofthe first uplink data TB after the transmission of the second uplink TB.The method determines to resume or not to resume the transmission of thefirst uplink TB based on the indication. The method resumes thetransmission of the first uplink TB in the first TTI TB after thetransmission of the second uplink TB if a UE has determined to resumethe transmission of the first uplink TB, wherein the first TTI length islarger than the second TTI length, the first and the second TTI overlapat least in one symbol, the first TTI starts earlier than the secondTTI. An apparatus also performs the functions of the method.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the embodiments briefly described abovewill be rendered by reference to specific embodiments that areillustrated in the appended drawings. Understanding that these drawingsdepict only some embodiments and are not therefore to be considered tobe limiting of scope, the embodiments will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings, in which:

FIG. 1A is a schematic block diagram illustrating one embodiment of acommunication system;

FIG. 1B is a schematic diagram illustrating one embodiment of a subframe13;

FIG. 1C is a schematic diagram illustrating one embodiment of asubframe;

FIG. 1D is a schematic diagram illustrating one alternate embodiment ofsTTI pattern of symbols;

FIG. 1E is a schematic diagram illustrating one embodiment of physicaluplink shared channel (PUSCH) resumption;

FIG. 1F is a schematic diagram illustrating one embodiment of a PUSCHdemodulation reference signal (DMRS) colliding with an sTTItransmission;

FIG. 1G is a schematic diagram illustrating one embodiment of a PUSCHDMRS colliding with an sTTI transmission;

FIG. 1H is a schematic diagram illustrating one embodiment of a PUSCHcolliding with an sTTI transmission;

FIG. 2A is a schematic diagram illustrating one embodiment of a PUSCHDMRS colliding with an sTTI transmission;

FIG. 2B is a schematic diagram illustrating one embodiment of uplinkcontrol information (UCI) mapping;

FIG. 2C is a schematic diagram illustrating a shortened PUSCH grantbeing the latest grant before a PUSCH grant;

FIG. 2D is a schematic diagram illustrating using same fc parameter forPUSCH transmissions;

FIG. 2E is a schematic block data illustrating one embodiment of systemdata;

FIG. 3A is a schematic diagram illustrating one embodiment of PUSCHresumption;

FIG. 3B is a schematic diagram illustrating one alternate embodiment ofPUSCH resumption;

FIG. 3C is a schematic diagram illustrating one alternate embodiment ofPUSCH resumption;

FIG. 3D is a schematic diagram illustrating one alternate embodiment ofPUSCH resumption;

FIG. 4 is a schematic block diagram illustrating one embodiment of userequipment;

FIGS. 5A-B are a schematic flow chart diagram illustrating oneembodiment of a TTI resumption method;

FIG. 5C is a schematic flow chart diagram illustrating one embodiment ofa TTI overlap method;

FIG. 5D is a schematic flow chart diagram illustrating one embodiment ofa resumption method; and

FIG. 5E is a schematic flow chart diagram illustrating one alternateembodiment of a resumption method.

DETAILED DESCRIPTION

As will be appreciated by one skilled in the art, aspects of theembodiments may be embodied as a system, method or program product.Accordingly, embodiments may take the form of an entirely hardwareembodiment, an entirely software embodiment (including firmware,resident software, micro-code, etc.) or an embodiment combining softwareand hardware aspects that may all generally be referred to herein as a“circuit,” “module” or “system.” Furthermore, embodiments may take theform of a program product embodied in one or more computer readablestorage devices storing machine readable code, computer readable code,and/or program code, referred hereafter as code. The storage devices maybe tangible, non-transitory, and/or non-transmission. The storagedevices may not embody signals. In a certain embodiment, the storagedevices only employ signals for accessing code.

Many of the functional units described in this specification have beenlabeled as modules, in order to more particularly emphasize theirimplementation independence. For example, a module may be implemented asa hardware circuit comprising custom VLSI circuits or gate arrays,off-the-shelf semiconductors such as logic chips, transistors, or otherdiscrete components. A module may also be implemented in programmablehardware devices such as field programmable gate arrays, programmablearray logic, programmable logic devices or the like.

Modules may also be implemented in code and/or software for execution byvarious types of processors. An identified module of code may, forinstance, comprise one or more physical or logical blocks of executablecode which may, for instance, be organized as an object, procedure, orfunction. Nevertheless, the executables of an identified module need notbe physically located together, but may comprise disparate instructionsstored in different locations which, when joined logically together,comprise the module and achieve the stated purpose for the module.

Indeed, a module of code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be identified and illustrated hereinwithin modules, and may be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data may becollected as a single data set, or may be distributed over differentlocations including over different computer readable storage devices.Where a module or portions of a module are implemented in software, thesoftware portions are stored on one or more computer readable storagedevices.

Any combination of one or more computer readable medium may be utilized.The computer readable medium may be a computer readable storage medium.The computer readable storage medium may be a storage device storing thecode. The storage device may be, for example, but not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, holographic,micromechanical, or semiconductor system, apparatus, or device, or anysuitable combination of the foregoing.

More specific examples (a non-exhaustive list) of the storage devicewould include the following: an electrical connection having one or morewires, a portable computer diskette, a hard disk, a random access memory(RAM), a read-only memory (ROM), an erasable programmable read-onlymemory (EPROM or Flash memory), a portable compact disc read-only memory(CD-ROM), an optical storage device, a magnetic storage device, or anysuitable combination of the foregoing. In the context of this document,a computer readable storage medium may be any tangible medium that cancontain, or store a program for use by or in connection with aninstruction execution system, apparatus, or device.

Code for carrying out operations for embodiments may be written in anycombination of one or more programming languages including an objectoriented programming language such as Python, Ruby, Java, Smalltalk,C++, or the like, and conventional procedural programming languages,such as the “C” programming language, or the like, and/or machinelanguages such as assembly languages. The code may execute entirely onthe user's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer or server. In the latterscenario, the remote computer may be connected to the user's computerthrough any type of network, including a local area network (LAN) or awide area network (WAN), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider).

Reference throughout this specification to “one embodiment,” “anembodiment,” or similar language means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment. Thus, appearances of the phrases“in one embodiment,” “in an embodiment,” and similar language throughoutthis specification may, but do not necessarily, all refer to the sameembodiment, but mean “one or more but not all embodiments” unlessexpressly specified otherwise. The terms “including,” “comprising,”“having,” and variations thereof mean “including but not limited to,”unless expressly specified otherwise. An enumerated listing of itemsdoes not imply that any or all of the items are mutually exclusive,unless expressly specified otherwise. The terms “a,” “an,” and “the”also refer to “one or more” unless expressly specified otherwise.

Furthermore, the described features, structures, or characteristics ofthe embodiments may be combined in any suitable manner. In the followingdescription, numerous specific details are provided, such as examples ofprogramming, software modules, user selections, network transactions,database queries, database structures, hardware modules, hardwarecircuits, hardware chips, etc., to provide a thorough understanding ofembodiments. One skilled in the relevant art will recognize, however,that embodiments may be practiced without one or more of the specificdetails, or with other methods, components, materials, and so forth. Inother instances, well-known structures, materials, or operations are notshown or described in detail to avoid obscuring aspects of anembodiment.

Aspects of the embodiments are described below with reference toschematic flowchart diagrams and/or schematic block diagrams of methods,apparatuses, systems, and program products according to embodiments. Itwill be understood that each block of the schematic flowchart diagramsand/or schematic block diagrams, and combinations of blocks in theschematic flowchart diagrams and/or schematic block diagrams, can beimplemented by code. The code may be provided to a processor of ageneral purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the functions/acts specified in the schematic flowchartdiagrams and/or schematic block diagrams block or blocks.

The code may also be stored in a storage device that can direct acomputer, other programmable data processing apparatus, or other devicesto function in a particular manner, such that the instructions stored inthe storage device produce an article of manufacture includinginstructions which implement the function/act specified in the schematicflowchart diagrams and/or schematic block diagrams block or blocks.

The code may also be loaded onto a computer, other programmable dataprocessing apparatus, or other devices to cause a series of operationalsteps to be performed on the computer, other programmable apparatus orother devices to produce a computer implemented process such that thecode which execute on the computer or other programmable apparatusprovide processes for implementing the functions/acts specified in theflowchart and/or block diagram block or blocks.

The schematic flowchart diagrams and/or schematic block diagrams in theFigures illustrate the architecture, functionality, and operation ofpossible implementations of apparatuses, systems, methods and programproducts according to various embodiments. In this regard, each block inthe schematic flowchart diagrams and/or schematic block diagrams mayrepresent a module, segment, or portion of code, which comprises one ormore executable instructions of the code for implementing the specifiedlogical function(s).

It should also be noted that, in some alternative implementations, thefunctions noted in the block may occur out of the order noted in theFigures. For example, two blocks shown in succession may, in fact, beexecuted substantially concurrently, or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved. Other steps and methods may be conceived that are equivalentin function, logic, or effect to one or more blocks, or portionsthereof, of the illustrated Figures.

Although various arrow types and line types may be employed in theflowchart and/or block diagrams, they are understood not to limit thescope of the corresponding embodiments. Indeed, some arrows or otherconnectors may be used to indicate only the logical flow of the depictedembodiment. For instance, an arrow may indicate a waiting or monitoringperiod of unspecified duration between enumerated steps of the depictedembodiment. It will also be noted that each block of the block diagramsand/or flowchart diagrams, and combinations of blocks in the blockdiagrams and/or flowchart diagrams, can be implemented by specialpurpose hardware-based systems that perform the specified functions oracts, or combinations of special purpose hardware and code.

The description of elements in each figure may refer to elements ofproceeding figures. Like numbers refer to like elements in all figures,including alternate embodiments of like elements.

FIG. 1A is a schematic block diagram illustrating one embodiment of acommunication system 100. The system 100 includes one or more evolvednode B (eNB) Long Term Evolution (LTE) base stations 105, referred tohereafter as eNB 105 and user equipment (UE) 110. An eNB 105 maycommunicate with the UE 110. The eNB 105 may be an evolved node B (eNB)Long Term Evolution (LTE) base station. The UE 110 may be a mobiletelephone, a machine-type communications (MTC) device, a tabletcomputer, a laptop computer, and embedded communication devices inautomobiles, kiosks, appliances, and the like.

FIG. 1B is a schematic block diagram illustrating one embodiment of asubframe 13. In the depicted embodiment, two slots 11 are shown. Slot 011 may be referred to as a first slot 11 and slot 1 11 may be referredto as a second slot 11. In current 3GPP (Third Generation PartnershipProject), time-frequency resources are divided into subframes where each1 ms subframe 13 comprises two 0.5 millisecond (ms) slots 11 and eachslot 11 comprises seven SC-FDMA symbols 10 in time domain in uplink (UL)and seven Orthogonal Frequency-Division Multiplexing (OFDM) symbols 10in time domain in downlink (DL). Each combination of a sub carrier 14and a symbol 10 forms a resource element 12. In the frequency domain,resource elements 12 within a slot are divided into physical resourceblocks (PRB), where each PRB spans contiguous subcarriers. Atransmission block (TB) may comprise a plurality of resource elements12.

In current LTE systems, resources such as resource elements 12 aretypically assigned using a 1 ms minimum transmission time interval (TTI)16 when data is available, referred to as dynamic scheduling. Withineach scheduled TTI 16, in UL, the UE 110 transmits data using a TB suchas a PUSCH in PRB-pairs indicated by an uplink grant to the UE 110 thatschedules the data transmission. In DL, the eNB 105 transmits data overa physical downlink shared channel (PDSCH) in PRB-pairs indicated by aDL grant/assignment. The UL grant and/or DL assignment information isprovided to the UE 110 in a control channel, referred to as a (enhanced)physical downlink control channel (E)PDCCH. The (E)PDCCH channel (insubframe n) carries the control information about the DL data beingtransmitted in the current subframe (subframe n) and the controlinformation about the UL resources which UE 110 need to use for theuplink data transmission in subframe n+k (k>=0).

A UE 110 shall monitor a set of (E)PDCCH candidates for controlinformation, where monitoring implies attempting to decode each of the(E)PDCCH decoding candidates in the set according to the monitored DCIformats. The set of (E)PDCCH candidates to monitor are defined in termsof (E)PDCCH search spaces.

UL DMRS Aspects

FIG. 1C shows one embodiment of a subframe 13. In LTE, the UL data andsome control information which may be UCI containing acknowledgement/nonacknowledgement (A/N), channel quality indicator (CQI), rank indicator(RI), pre-coding matrix indicator (PMI), procedure transaction indicator(PTI), contention resolution identity (CRI) is sent in PUSCH 21. ThePUSCH 21 can have DMRS 23 which an eNB 105 can use to demodulate thePUSCH in SC-FDMA symbols 10 as shown. The location of DMRS 23 may befixed for all UEs 110 in symbols 3 and 10 within the subframe.

A UE 110 receiving an UL grant for PUSCH transmission can be assignedcyclic shifts (CS) and orthogonal cover codes (OCC) for DMRS 23transmission (multiple CS and OCC pairs for different layers in UL MIMOtransmission). The use of CS and OCC helps the eNB 105 to orthogonalizeor make separable simultaneous UL DMRS transmissions (from the same UEin different layers, or from multiple UEs) received at the eNB 105.Table 5.5.2.1.1-1 from the LTE 36.211 specification shows the OCC codesand CSs. As shown in Table 5.5.2.1.1-1, the OCC assignment is based onthe 3-bit cyclic shift field in the UL DCI, and number of layertransmission (layer λ∈{0, 1, . . . , υ−1}, where υ is the number oflayers) scheduled by UL DCI.

Table 5.5.2.1.1-1 Mapping of Cyclic Shift Field in uplink-related DCIformat to n_(DMRS,λ) ⁽²⁾ and [w^((λ))(0) w^((λ))(1)]

Cyclic Shift in Field uplink- related DCI η_(DMRS,λ) ⁽²⁾ [w^((λ))(0)w^((λ))(1)] format [3] λ = 0 λ = 1 λ = 2 λ = 3 λ = 0 λ = 1 λ = 2 λ = 3000 0 6 3 9 [1 1] [1 1] [1 −1] [1 −1] 001 6 0 9 3 [1 −1] [1 −1] [1 1] [11] 010 3 9 6 0 [1 −1] [1 −1] [1 1] [1 1] 011 4 10 7 1 [1 1] [1 1] [1 1][1 1] 100 2 8 5 11 [1 1] [1 1] [1 1] [1 1] 101 8 2 11 5 [1 −1] [1 −1] [1−1] [1 −1] 110 10 4 1 7 [1 −1] [1 −1] [1 −1] [1 −1] 111 9 3 0 6 [1 1] [11] [1 −1] [1 −1]

UL Power Control Aspects

The UE 110 may determine transmit power P for a subframe/TTI as P=10 log10(M_(PUSCH,c)(i))+P_(O_PUSCH,c)(j)+α_(c)(j)PL_(c)+Δ_(TF,c)(i)+f_(c)(i),wherein M_(PUSCH,c)(i) is a number of resource blocks, P_(O_PUSCH,c))(j)is a target received power signaled to the UE over radio resourcecontrol (RRC), α_(c)(j)PL_(c) is a scaled downlink path loss estimatewith 0≤α_(c)(j)≤1 signaled to the UE over the RRC, Δ_(TF,c)(i) is anadjustment factor, f_(c) is an ith power control adjustment state and iscalculated as one of f_(c)(i)=f_(c)(i−1)+δ_(PUSCH,c)(i−K_(PUSCH)) andf_(c)(i)=f_(c)(i)+δ_(PUSCH,c)(i−K_(PUSCH)).

Reduced Latency Operation

To reduce latency of communication in LTE, various embodiments may beemployed. For example, an approach envisioned for future LTE systems isto use shorter minimum TTI 15, i.e., shorter than 1 ms or 2 slots or 1subframe TTI/allocation for PUSCH 21 and physical downlink sharedchannel (PDSCH), in UL/DL. Using a shorter minimum TTI (sTTI) 15 allowsthe UE 110 to send/receive data using reduced latency when compared tocurrent LTE systems. In addition, acknowledging each (or a groupcontaining few) sTTI(s) 15 leading to faster (compared to using 1 ms TTI16) acknowledging data can help in some applications such astransmission control protocol (TCP) during slow-start phase for users ingood channel conditions. For example, in the TCP slow-start phase for DLcommunication, the network-UE link capacity for a user in good channelcondition can support more data; but the network sends a smaller amountof data because the network is waiting to receive the acknowledgment forthe previously sent data due to the TCP slow-start phase. Therefore,faster acknowledgments (e.g., as a result of using shorter TTI length)would enable the network to better utilize the available network-UE linkcapacity.

For example, scheduling UE transmission over a sTTI length of 0.5 ms(i.e., sPUSCH (shortened PUSCH) scheduled using a PRB spanning a 0.5 msslot 11 in a 1 ms subframe 13), or scheduling UE transmission over asTTI length of ˜140 us (i.e., PUSCH scheduled using a shortened PRBspanning 2 SC-FDMA symbols 10 within a slot 11 in a subframe 13), wouldnot only reduce time taken to start/finish transmitting a data packet,but also potentially reduce the round trip time for possible hybridautomatic repeat request (HARD) retransmissions related to that datapacket.

FIG. 1D shows an alternate sTTI pattern of symbols 10 per subframe 13for 2-symbol DL TTI and a CC (component carrier) configured with a2-symbol sTTI operation, for a cross-carrier scheduled CC, the startingsymbol index of the first potential sPDSCH is configured by RRC. For aself-carrier scheduled CC, the starting symbol index of the firstpotential sPDSCH equals to a control format indicator (CFI) valueindicated by a physical control format indicator channel (PCFICH). Table1 illustrates one embodiment of the UE 110 determining the sTTI pattern.

TABLE 1 The starting symbol index of the first potential sPDSCH2-symbols DL sTTI pattern 1, 3 FIG. 1C 2 FIG. 1D

For uplink (UL), for 2/3-OFDM based sTTI 15, the UL sTTI pattern forsPUSCH (i.e., UL data which may carry some UL control information) andsPUCCH (i.e., UL control information) of FIG. 1C may be employed.

A UE 110 may be dynamically scheduled with PUSCH and/or sPUSCH” with asubframe 13 to subframe 13 granularity. For UL transmission, in case ofcollision between PUSCH and sPUSCH in the same subframe 13 on a givencarrier for a UE 110, The UE 110 may transmit sPUSCH. In addition, theUE 110 may stop/drop the transmission of PUSCH with either partial orfull stopping/dropping. In one embodiment, the UE 110 may transmit UCIof PUSCH if the PUSCH carries the UCI(s).

FIG. 1E illustrates one embodiment of PUSCH resumption. When feasible,resuming PUSCH transmission, comprising at least one or more transportblocks (TB) and optionally UCI, after sTTI transmission, whereininterrupted and then resumed PUSCH transmission is referred to hereafteras punctured PUSCH 21, may improve PUSCH 21 decoding performance. TheeNB 105 may be able to decode the punctured PUSCH 21 or it may combinethe punctured PUSCH 21 with previously received PUSCH 21 for the sameTB(s) to decode the PUSCH data. In the depicted embodiment, the UE 110stops PUSCH transmission at sTTI3 15. The UE 110 further transmits asTTI related signal such as a sPUSCH 27 containing UL data and/orcontrol, or sPUCCH 27 containing UL control information. Then, aftersTTI3 15, the UE 110 resumes the PUSCH transmission.

In LTE, for UL transmission, such as for different UL channels such asPUSCH (physical uplink shared channel) and PUCCH (physical uplinkcontrol channel), the transmit power of the UE 110 is controlled by setof mechanisms referred to as UL power control.

Embodiments

The embodiments manage collisions of UL sTTI 15 (e.g., 2 or 3 or 7symbol TTI) and regular TTI 16 (e.g., 1 ms). In one example, thenumerology of the UL sTTI 15 may be different than the numerology forthe regular TTI 16. For example, the subcarrier spacing of the UL sTTI15 may be 60 kHz while the subcarrier spacing of the regular TTI 16 maybe 15 KHz. The number of symbols 10 comprising the sTTI 15 may be samewith a larger subcarrier spacing for the sTTI 15 compared to the regularTTI 16.

Resuming PUSCH after sTTI Transmission

When feasible, resuming PUSCH transmission after sTTI transmission mayimprove PUSCH decoding performance. For instance, when a PUSCH DMRS 23is overlapped with sTTI transmission, there are scenarios where resumingPUSCH transmission in non-overlapping symbols between PUSCH 21 and sTTI15 may not be helpful, and resuming PUSCH transmission may potentiallyblock resource elements 12 to be scheduled for other sTTI UEs 110 in theremaining of the subframe 13, or may affect PUSCH decoding performanceof other potentially paired PUSCH UEs 110 in case of multiuser MIMO(MU-MIMO).

FIG. 1F illustrates a PUSCH DMRS 23 in slot 0 11 colliding with an sTTItransmission in sTTI1 15, specifically a sPUSCH 27, when intra-TTI PUSCHhopping is set. In the depicted embodiment, PUSCH transmission may notbe beneficially resumed in slot 0 11 (i.e., PUSCH 21 a in sTTI2 15) asSC-FDMA symbols 10 cannot be demodulated due to missing the DMRS 23.

FIG. 1G illustrates a PUSCH DMRS 23 in slot 1 11 colliding with an sTTItransmission in sTTI1 15, specifically a sPUSCH 27, when intra-TTI PUSCHhopping is set. In the depicted embodiment, PUSCH transmission may notbe beneficially resumed in slot 1 11 (i.e., PUSCH 21 a in sTTI5 15) asSC-FDMA symbols 10 cannot be demodulated due to missing the DMRS 23.

FIG. 1H illustrates a PUSCH 21 colliding with a sTTI transmission,specifically an sPUSCH 27 in slot 0 11. In the depicted embodiment, thePUSCH transmission in slot 0 11 is not useful as intra-TTI hopping isset for PUSCH transmission and PUSCH DMRS 23 is collided with the sTTItransmission. As a result, PUSCH transmission is not resumed in slot 011 and also not resumed in slot 1 11. In one example, if intra-TTIhopping PUSCH DMRS 23 is dropped (not set) to transmit sTTI 15 in a slot11 (e.g., slot 0), PUSCH transmission is resumed at the next slotboundary (e.g., slot 1 as in FIG. 1F).

In another example, the UE may be configured by higher layers (layersabove physical layer) on whether to resume the PUSCH transmission incase of collision with sTTI 15. In some embodiments, the configurationmay apply to any collision of PUSCH 21 and sTTI 15. In otherembodiments, the configuration may apply to only in case of collision ofPUSCH DMRS 23 and sTTI 15. In other embodiments, the UE 110 may beconfigured with separate configurations for case of intra-TTI hoppingand no intra-TTI hopping.

In another example, if the UE 110 is configured to resume PUSCH 21, theUE 21 may resume PUSCH transmission in next slot 11, in case ofcollision between intra-TTI hopping PUSCH DMRS and sTTI for a UE. Anexample of UE 110 configured to not resume PUSCH transmission aftercollision with sTTI 15 is shown in FIG. 1H.

In case of uplink subframe bundling with PUSCH transmission spanningmultiple subframes 13 for a UE 110, in one embodiment for a collision ofPUSCH 21 and sTTI 15 in a first subframe 13, the UE 110 may drop theremaining PUSCH transmission in the subframe 13 as shown in FIG. 1H, andresume PUSCH transmission in a second subframe 13 within the allocatedmultiple subframes 13. The second subframe 13 may be the next subframe13 after the first subframe 13. In one example the collision of PUSCH 21and sTTI 15 correspond to the collision of PUSCH DMRS 23 and sTTI 15.

In another embodiment for uplink subframe bundling and intra-TTIhopping, the UE 110 may resume PUSCH transmission in a next slot 13within the allocated slots 13 for a collision between intra-TTI hoppingPUSCH DMRS 21 and sTTI 15 for a UE 110.

In embodiment, the UE 110 may be assigned a one of the DMRS OCC code(i.e., [1 1] or [1 −1] refer to Table 5.5.2.1.1-1 from 36.211), resumingits PUSCH transmission after sTTI transmission can cause PUSCHperformance degradation due to multiuser (MU) interference if anotherPUSCH UE has been paired with the UE 110 with partially overlappedfrequency resources in the subframe using the other DMRS OCC code. Thisis due to the loss of OCC orthogonality and inter-UE MU interference onthe reference signals of the paired UEs 110.

For example, if the first UE 110 and the second UE 110 have been pairedfor multiuser multiple-input multiple-output (MU-MIMO) UL transmissionas shown in FIG. 2A, due to DMRS dropping in the slot0 by UE1, DMRSseparation between UE1 and UE2 via OCC is not possible, so it is betterto have UE1 stop PUSCH transmission for the subframe after transmittingsTTI in sTTI1.

FIG. 2A illustrates one embodiment of a PUSCH DMRS 23 of a UE 110 inslot 0 13 colliding with sTTI transmission in sTTI1 15. In the depictedembodiment, a first UE 110 and a second UE 110 are paired for MU-MIMOPUSCH transmissions in the subframe 13. The first UE 110 may beallocated RBs #10-30 41 and the second UE 110 may be allocated RBs#18-24 43. The first UE 110 may be scheduled for sPUSCH transmission insTTI1 15 over RBs #10-40 45. The first UE 110 may be assigned CS fieldvalue=011 with rank1 (hence OCC=[1 1] for single layer) for PUSCH, andthe second UE 110 may be assigned CS field value=010 (hence OCC=[1 −1]for both layer 0 and layer 1) with rank2. Since the first UE 110 doesnot transmit PUSCH DMRS in symbol 3 10 in the subframe 13 due to an sTTItransmission in sTTI1 15, if the first UE 110 resumes transmitting PUSCHafter sTTI1 15, the eNB 105 may not be able to separate the DMRS 23 ofthe first and second UE 110 and reliably decode PUSCH 21 for the firstand second UE 110, since the DMRS 23 should have been separated by OCCcodes, but the separation is not possible due to absence of DMRStransmission in symbol 3 10 by the first UE 110. So, the first UE 110does not transmit PUSCH 21 after transmitting sPUSCH 27.

However, if the eNB 110 does not perform MU-pairing or only pairs UEs110 with the same resource allocation, and different DMRS cyclic shiftsresuming PUSCH 21 is beneficial. Considering that any MU-MIMO istransparent to the UE 110 and resuming PUSCH transmission is beneficialprovided that any intra-cell MU interference can be sufficientlysuppressed, it may be beneficial to give the eNB 105 the flexibility toenable/disable resuming PUSCH 21 after sTTI transmission depending onwhether and how MU-MIMO is supported in the cell. In one embodiment, theeNB 105 may configure a UE 110 to resume or drop PUSCH transmissionafter sTTI transmission. In another embodiment, the eNB 105 mayconfigure a UE 110 to resume or drop non-intra TTI hopping PUSCHtransmission (after sTTI transmission) in case of collision betweenPUSCH DMRS 23 and sTTI 15.

Such enabling/disabling of resuming PUSCH transmission is possible byhigher layer signaling such as RRC, medium access control (MAC) controlelement (CE), or by physical layer signaling such as enhanced physicaldownlink control channel (E)PDCCH or shortened physical downlink controlchannel (sPDCCH) earlier (e.g., in a previous sTTI 15 or subframe 13).

In one example, if a UE 110 is assigned both the OCC codes (e.g.,corresponding to rank more than 2, transmission rank 3, 4 in Table5.5.2.1.1-1 for CS field value of 000), then the UE 110 may resume PUSCHtransmission after sTTI transmission in case of collision between sTTI15 and PUCSH 21. The collision may be between the PUSCH DMRS 23 and sTTI15 in which case the other DMRS 23 is separable due to use of differentcyclic shifts. In one example, the resumption of PUSCH transmissionafter sTTI transmission is based on the rank of the PUSCH transmission.For example, resume if rank>2, and don't resume otherwise. In anotherexample, the resumption of PUSCH transmission after sTTI transmission isbased on the rank of the PUSCH transmission and DM-RS cyclic shiftcombinations. In other example, the resumption of PUSCH transmissionafter sTTI transmission is based on the value of the cyclic shift field,for example for a first set of cyclic shift field values resume PUSCHtransmission, while for another set of cyclic shift values drop or donot resume the PUSCH transmission.

PUSCH and sTTI Collision from System Perspective

If a UE 110 is scheduled for PUSCH transmission in subframe “n,” anotherUE 110 may not be scheduled for sTTI transmission in that subframe 13 inoverlapping resources due to time difference in regular TTI 16 and sTTI15 scheduling timeline, otherwise will result in introduction ofintra-cell MU interference. The eNB 105 may schedule regular TTI andsTTI UEs 110 in non-overlapping resources.

In addition, another UE 110 may be scheduled for sTTI transmission inthat subframe 13 in overlapping resources if the eNB receiver can dealwith the MU interference due to resource overlap e.g., via detectinghigh interference on PUSCH symbols (assuming no sTTI collision on PUSCHDMRS), MU interference suppression on the overlapped PUSCH symbols,and/or weighting the LLRs accordingly (assuming no sTTI collision onPUSCH DMRS for reliable channel estimates).

Overlapped PUSCH UCI Handling

FIG. 2B illustrates one embodiment of UCI mapping. RI 31, A/N 33, andDMRS 23 are shown allocated to symbols 10. In one embodiment, PUSCH 21may be stopped/dropped for a UE 110 if PUSCH 21 and sPUSCH 27 areoverlapped within a subframe 13. The UCI which was supposed to becarried on PUSCH 21 may be mapped onto sPUSCH 27, at least for sPDSCHHARQ-A/N 33 and/or RI 31.

For the A/N 33 and RI 31 mapping on PUSCH 21, if some of the SC-FDMAsymbols 10 containing A/N are not collided with by a sTTI transmission,the SC-FDMA symbols 10 can be used to minimize resources needed onsPUSCH 27 to carry PUSCH UCI. For instance, if sTTI transmission occursonly in sTTI5 15, and PUSCH 21 has been transmitted in the subframe 13up to sTTI5 15, the number of PDSCH A/N REs 12 required on sPUSCH 27 maybe smaller than that of the case where the PUSCH 21 had been droppedcompletely from the beginning or than the case when the PDSCH A/N REs onsPUSCH 27 are dimensioned ignoring the A/N transmission that haveoccurred on PUSCH 21. In one example, for a PDSCH ACK/NACK payload (ornumber of REs 12 needed) on sPUSCH referred to as “X5.”

In another example, if sTTI transmission occurs only in sTTI4 15, andPUSCH 21 has been transmitted in the subframe 13 up to sTTI4 15, thenumber of A/N REs 12 on sPUSCH 27 can be smaller than that of the casewhere the PUSCH 21 had been dropped completely from the beginning and/orthan the case when the PDSCH A/N REs 12 on sPUSCH 27 are dimensionedignoring the A/N transmission that have occurred on PUSCH 21. SincesTTI4 15 collides with PUSCH DMRS 23, the PDSCH A/N payload (or numberof REs 12 needed) on sPUSCH 27, referred to as “X4”, may be larger thanthat of “X5” for the same channel and transmission parameters.

In another example, if sTTI transmission occurs at least in sTTI0 15,only a part of the PDSCH A/N payload is transmitted on sPUSCH 27 insTTI0 if PUSCH 21 is supposed to be resumed after sTTI0 15, since therest of the PDSCH A/N payload may be transmitted in their originallocations in PUSCH 21 (i.e., symbols 4, 9, and 11). If those symbols 10are dropped due to additional sTTI transmissions, those sTTItransmissions also carry a part of the PDSCH ACK-NACK payload.

Similar rules can be applied for RI 31 instead of PDSCH A/N 33.

In one example, when only one transport block is transmitted in thePUSCH conveying the HARQ-ACK bits, rank indicator bits or CRI bits, thenumber of coded modulation symbols per layer Q′ for HARQ-ACK, rankindicator, or CRI bits on PUSCH is given by Equation 1.

$\begin{matrix}{Q^{\prime} = {\min\left( {\left\lbrack \frac{\begin{matrix}{O \cdot M_{SC}^{{PUSCH} - {initial}} \cdot} \\{N_{symb}^{{PUSCH} - {initial}} \cdot \beta_{offset}^{PUSCH}}\end{matrix}}{\sum\limits_{r = 0}^{C - 1}\; K_{r}} \right\rbrack,{4 \cdot M_{SC}^{PUSCH}}} \right)}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

where O is the number of HARQ-ACK bits, rank indicator bits or CRI bits,M_(sc) ^(PUSCH) is the scheduled bandwidth for PUSCH transmission in thecurrent sub-frame for the transport block, expressed as a number ofsubcarriers, N_(sym) ^(PUSCH-initial) is the number of SC-FDMA symbolsper subframe for initial PUSCH transmission for the same transportblock, M_(sc) ^(PUSCH-initial), C, and K_(r) are obtained from theinitial PDCCH or EPDCCH for the same transport block, or the most recentsemi-persistent scheduling assignment PDCCH or EPDCCH when the initialPUSCH for the same transport block is semi-persistently scheduled, orwherein the random access response grant for the same transport block,when the PUSCH 21 is initiated by the random access response grant.

In one embodiment, C is the number of code blocks of the transport block(after segmentation) and K_(r) is the number of bits for code blocknumber r. β_(offset) ^(PUSCH), β_(offset) ^(sPUSCH) may be an offsetvalue (>=1) for PUSCH, and may be different for HARQ-A/N 33 and RI 31,and CRI and may be dependent on the number of PUSCH layers or number ofcodewords on PUSCH 21.

In one embodiment, only a fraction (α) of the coded modulation symbols10 per layer Q′ is transmitted on PUSCH 21 before the collision withsTTI, the number of coded modulation symbols per layer Q″ on sPUSCH/sTTIcan be determined using Equation 2.

$\begin{matrix}{Q^{''} = \frac{\left( {1 - \alpha} \right){Q^{\prime} \cdot m_{1}^{PUSCH} \cdot \beta_{offset}^{PUSCH}}}{m_{2}^{sPUSCH} \cdot \beta_{offset}^{sPUSCH}}} & {{Equation}\mspace{14mu} 2}\end{matrix}$

Wherein in Equation 2,

$m_{1}^{PUSCH} = \frac{\sum\limits_{r = 0}^{C - 1}\; K_{r}}{M_{SC}^{{PUSCH} - {initial}} \cdot N_{symb}^{{PUSCH} - {initial}}}$is a representation of the modulation and coding rate for the PUSCH TB,and

$m_{1}^{sPUSCH} = \frac{\sum\limits_{r = 0}^{C^{\prime} - 1}\; K_{r}^{\prime}}{M_{SC}^{{sPUSCH} - {initial}} \cdot N_{symb}^{{sPUSCH} - {initial}}}$is a representation of the modulation and coding rate for the sPUSCH TB,N_(symb) ^(sPUSCH-initial) is the number of SC-FDMA symbols for sTTI forinitial sPUSCH transmission for the same transport block, M_(SC)^(sPUSCH-initial), C′, and K_(r)′ are obtained from the initial PDCCH orEPDCCH for the same transport block on sPUSCH 27, or the most recentsemi-persistent scheduling assignment PDCCH or EPDCCH when the initialsPUSCH for the same transport block is semi-persistently scheduled, or,the random access response grant for the same transport block, when thesPUSCH 27 is initiated by the random access response grant. In addition,C′ may be the number of code blocks of the transport block (aftersegmentation) for sPUSCH, K_(r)′ may be the number of bits for codeblock number r, δ_(offset) ^(sPUSCH) is an offset value (>=1) forsPUSCH, and may be different for HARQ-ACK, RI, CRI and may be dependenton the number of sPUSCH layers or number of codewords on sPUSCH. Thenumber of coded modulation symbols per layer Q″ on sPUSCH/sTTI may beupper bounded by a particular value.

In one embodiment, the number of coded modulation symbols per layer Q″on sPUSCH 27 may be based on the number of SC-FDMA symbols in the sTTI.In a certain embodiment, when one PUSCH SC-FDMA symbol 10 containing A/N33 (out of the 4) is dropped (sTTI 5 transmission), α=1/4.

A similar procedure for determining the number of coded modulationsymbols per layer Q″ on sPUSCH 27/sTTI 15 can be applied when multipletransport blocks are transmitted on PUSCH 21 and/or sPUSCH 27. Forexample, the case when two transport blocks (denoted (1) and (2) insuper-script in the equations below) are transmitted in the PUSCHconveying the HARQ-ACK bits, rank indicator bits or CRI bits as inEquation 3:

$\begin{matrix}{Q^{\prime}{\max\left\lbrack {{\min\left( {Q_{temp}^{\prime},{4 \cdot M_{SC}^{PUSCH}}} \right)},Q_{\min}^{\prime}} \right\rbrack}} & {{Equation}\mspace{14mu} 3} \\{Q_{temp}^{\prime} = \left\lbrack \frac{\begin{matrix}{O \cdot M_{SC}^{{PUSCH} - {{initial}{(1)}}} \cdot N_{symb}^{{PUSCH} - {{initial}{(1)}}} \cdot} \\{M_{SC}^{{PUSCH} - {{initial}{(2)}}} \cdot N_{symb}^{{PUSCH} - {{initial}{(2)}}} \cdot \beta_{offset}^{PUSCH}}\end{matrix}}{\begin{matrix}{{\sum\limits_{r = 0}^{C^{(1)}}\;{K_{r}^{(1)} \cdot M_{SC}^{{PUSCH} - {{initial}{(2)}}} \cdot N_{symb}^{{PUSCH} - {{initial}{(2)}}}}} +} \\{\sum\limits_{r = 0}^{C^{(2)}}\;{K_{r}^{(2)} \cdot M_{SC}^{{PUSCH} - {{initial}{(1)}}} \cdot N_{symb}^{{PUSCH} - {{initial}{(1)}}}}}\end{matrix}} \right\rbrack} & {{Equation}\mspace{14mu} 4} \\{m_{1}^{PUSCH} = \frac{{\sum\limits_{r = 0}^{C^{(1)}}\; K_{r}^{(1)}} + {\sum\limits_{r = 0}^{C^{(2)}}\; K_{r}^{(2)}}}{\begin{matrix}{{M_{SC}^{{PUSCH} - {{initial}{(1)}}} \cdot N_{symb}^{{PUSCH} - {{initial}{(1)}}}} +} \\{M_{SC}^{{PUSCH} - {{initial}{(2)}}} \cdot N_{symb}^{{PUSCH} - {{initial}{(2)}}}}\end{matrix}}} & {{Equation}\mspace{14mu} 5}\end{matrix}$

Equation 4 is a representation of the modulation and coding rate for thetwo PUSCH TBs. Equation 5 is a representation of the modulation andcoding rate for two sPUSCH TBs.

$\begin{matrix}{m_{1}^{sPUSCH} = {\frac{{\sum\limits_{r = 0}^{C^{(1)}}\; K_{r}^{\prime{(1)}}} + {\sum\limits_{r = 0}^{C^{(2)}}\; K_{r}^{\prime{(2)}}}}{\begin{matrix}{{M_{SC}^{{sPUSCH} - {{initial}{(1)}}} \cdot N_{symb}^{{sPUSCH} - {{initial}{(1)}}}} +} \\{M_{SC}^{{sPUSCH} - {{initial}{(2)}}} \cdot N_{symb}^{{sPUSCH} - {{initial}{(2)}}}}\end{matrix}}.}} & {{Equation}\mspace{14mu} 6}\end{matrix}$

Equation 6 is a representation of the modulation and coding rate for thetwo sPUSCH TBs.

Power Control Aspects

In one embodiment, the f_(c) parameter used in power control for sPUSCH27 and PUSCH 21 is calculated as follows:

If accumulation not activated for PUSCH 21 in subframe “n” 13, f_(c) isdetermined based on the UL grant (referred to here as UL_grant1)scheduling the PUSCH 21 (the grant can be sent in subframe “n−4” or“n−3” depending on whether reduced processing time is enabled for 1ms-TTI PUSCH transmission).

Alternatively, f_(c) for PUSCH transmission in subframe “n” 13 can bedetermined based on the UL grant (referred to here as UL_grant2)scheduling the latest sPUSCH 27 prior to subframe “n.” For example, if asPUSCH transmission happens at subframe “n−1,” 13 f_(c) for PUSCHtransmission in subframe “n” 13 can be determined according to the ULgrant scheduling sPUSCH transmission in subframe “n−1”. The UL grant(i.e., UL_grant2) for the sPUSCH in subframe “n−1” 13, might have beensent in subframe “n−2” 13.

Alternatively, f_(c) for PUSCH transmission in subframe “n” can bedetermined based on both the UL_grant1 and UL_grant2. For instance,f_(c) can be determined based on the weighted average of f_(c) obtainedfrom each grant: f_(c)=α₁f_(c) ^(PUSCH)+α₂f_(c) ^(sPUSCH), where f_(c)^(PUSCH), and f_(c) ^(sPUSCH) are the f_(c) derived based on UL_grant1,and UL_grant2, respectively, and α₁+α₂=1, and the weights (α₁, α₂) areboth positive. In a more general setting, f_(c)=G(f_(c) ^(PUSCH),f_(c)^(sPUSCH)), where G(a,b) is a function of “a” and “b”. The weights orthe function G(.,.) can be a function of the resource allocation forsPUSCH and PUSCH.

For sPUSCH in subframe “n”, f_(c) is determined based on the UL grantscheduling the sPUSCH transmission.

Alternatively, f_(c) can be determined based on a physical layer signalthat is valid for the subframe, which result in the same f_(c) appliedto all sTTIs 15 and PUSCH 21 in the subframe 13. A f_(c) that is ascaled version based on resource allocation of the sPUSCH 27 and theresource allocation indicated in the physical layer signal wherein thebasic f_(c) for PUSCH 21 is calculated.

If accumulation is activated for, a PUSCH 21 in subframe “i”,f_(c)(i)=f_(c)(i−1)+δ_(PUSCH,c)(i−K_(PUSCH)), whereδ_(PUSCH,c)(i−K_(PUSCH)) is the UL grant scheduling the PUSCH 21 (thegrant can be sent in subframe “n−4” or “n−3” depending on whetherreduced processing time is enabled for 1 ms-TTI PUSCH transmission), andwhere f_(c)(i−1) refers to the latest f_(c) that is calculated for priorPUSCH transmissions.

Alternatively, f_(c)(i−1) is derived based on the latest f_(c) that iscalculated for the latest prior PUSCH or sPUSCH transmissions, where theprior PUSCH or sPUSCH transmissions corresponding UL grant happenedbefore the UL grant scheduling the PUSCH transmission in subframe “i”.

In FIG. 2C illustrates one embodiment wherein an sPUSCH grant was thelatest grant before the PUSCH grant. Transmissions of a PUSCH 21 and asPUSCH 27 in UL 55 are shown along with an sPUSCH grant 51 and a PUSCHgrant 53 in the DL 57. To update fc for PUSCH power allocation whenaccumulation is activated, fc(i−1) is selected based on fc computed forthe latest sPUSCH transmission wherein the corresponding sPUSCH grant 51is the latest one before the PUSCH grant 53. If the latest UL grantbefore the PUSCH UL grant 53 was another PUSCH UL grant 53, that otherPUSCH UL grant 53 should be used for fc(i−1) calculation.

In one embodiment, sPUSCH 27 is scheduled for transmission in sTTI0 ofsubframe “i”, if PUSCH transmission starts after the sTTI0 (for examplefrom sTTI1), the fc(i) for the PUSCH 21 can be obtained based on thelatest UL grant before the PUSCH grant 53, or alternatively, based onthe latest UL grant before PUSCH transmission, or alternatively can beobtained based on f_(c)(i)=f_(c)(i−1) where the PUSCH grant 53 (i.e.,the term δ_(PUSCH,c)(i−K_(PUSCH))) is ignored.

Alternatively, f_(c)(i)=Y(f_(c)(i−1)), where Y(.) is a function, e.g.,can be Y(w)=a×w, where “a” is a coefficient determined by the UE 110based on higher layer signaling, physical layer signaling, or based onthe resource allocation, or based on the combinations of one or abovementioned parameters.

If accumulation is activated for sPUSCH 27 in sTTI “m” 15 (0<=m<=5) insubframe “i,” if there was another sTTI transmission in the subframe insTTI “m−1” 15, the fc for sPUSCH transmission can be obtained f_(c)^(s)(6i+m)=f_(c)(6i+m−1)+δ_(sPUSCH,c)(6i+m−K_(sPUSCH)) whereinf_(c)(6i+m−1) is obtained based on the prior sPUSCH transmission.

If there was another sTTI transmission in the subframe 13, before sTTI“m” 15, the fc for sPUSCH transmission (shown as f_(c) ^(sPUSCH)(6i+m))may be obtained f_(c)^(sPUSCH)(6i+m)=f_(c)(6i+m−1)+δ_(sPUSCH,c)(6i+m−K_(sPUSCH)), whereinf_(c)(6i+m−1) is obtained based on the latest sPUSCH transmission.Alternatively, if PUSCH 21 was being transmitted prior to the sPUSCH 27in subframe “i” 13, f_(c)(6i+m−1) can be obtained based on the fc usedfor PUSCH transmission prior to sPUSCH transmission in sTTI “m” 15.

Based on the latest f_(c)(6i+m−1) of alternative 1 and 2 above, if m=0,we can use the approaches mentioned in in the preceding paragraph. As aresult, f_(c)(6i+m−1) may employ one or two variants:

Variant 1: f_(c)(6i+m−1) can be obtained based on the fc computed forPUSCH transmission in subframe “i” 13 although it has not beentransmitted yet, i.e., f_(c) ^(sPUSCH)(6i+m)=f_(c)^(PUSCH)(i)+δ_(sPUSCH,c)(6i+m−K_(sPUSCH)).

Variant 2: f_(c)(6i+m−1) can be obtained based on the fc computed forPUSCH transmission in subframe “i−1” 13 or the latest prior subframe 13,i.e., f_(c) ^(sPUSCH)(6i+m)=f_(c)^(PUSCH)(i−1)+δ_(sPUSCH,c)(6i+m−K_(sPUSCH)).

If PUSCH 21 stopped and resumed in a subframe 13 due to sTTItransmissions, the PUSCH 21 uses the same fc and transmit power over thesubframe 13 (See FIG. 2D). In one example, the same fc that was computedfor PUSCH transmission earlier in the subframe 13. In one example, ifsPUSCH 27 is transmitted in a latest sTTI 15 before PUSCH 21 (e.g.,sTTI0) and no prior PUSCH transmission (e.g., no PUSCH bundling), thePUSCH 21 can use the fc value computed for the latest sTTI 15. Thelatest sTTI 15 may be latest sTTI 15 in the previous subframe or thelatest sTTI 15 since receiving the PUSCH UL grant 53, or the latest sTTIcorresponding to the latest sTTI UL grant 51 since receiving the PUSCHUL grant 53.

FIG. 2D illustrates using a same fc parameter for PUSCH transmissions inthe subframe 13. In the depicted embodiment, a single fc parameter isused for each PUSCH 21.

FIG. 2E is a schematic block data illustrating one embodiment of systemdata 200. The system data 200 may be organized as a data structure in amemory. In the depicted embodiment, the system data 200 includes anintra-TTI hopping value 201, a number of resource blocks 203, a targetpower received 205, a scaled path downlink loss estimate 207, anadjustment factor 209, power control adjustment states 211, cyclicshifts 213, orthogonal cover codes 215, a resumption policy 217, andtransmit power 219.

The intra-TTI hopping value 201 may indicate whether intra-TTI hoppingis enabled or disabled. The number of resource elements 203 may specifya number of RI 31 QRI and a number of A/N 33 QAN. The target powerreceived P_(O_PUSCH,c)(j) 205 may be received at the UE 110 over RRC.The scaled path downlink loss estimate α_(c)(j)PL_(c) 207, wherein0≤α_(c)(j)≤1, may be signaled to the UE 110 over the RRC. The adjustmentfactor Δ_(TF,c)(i) 209 may be based on a number of coded bits as definedin LTE 36.213.

The resumption policy 217 may be satisfied for PUSCH collision inresponse to the PUSCH 21 being for a high ranked transmission and cyclicshifts and orthogonal cover codes (OCC) comprising the DMRS 23. Theresumption policy 217 may not be not satisfied for PUSCH collision inresponse to the PUSCH 21 not being for a high ranked transmission andcyclic shifts and OCC not comprising the DMRS 23.

FIG. 3A is a schematic diagram illustrating one embodiment of PUSCHresumption. In the depicted embodiment, intra-TTI hopping is enabled anda PUSCH 21 collides with a DMRS 23. The PUSCH 21 a may resume at symbolS7 10 of slot 1 11.

FIG. 3B is a schematic diagram illustrating one alternate embodiment ofPUSCH resumption. In the depicted embodiment, intra-TTI hopping isenabled and a PUSCH 21 collides with a DMRS 23. The PUSCH 21 a mayresume at symbol S5 10 of slot 0 11.

FIG. 3C is a schematic diagram illustrating one alternate embodiment ofPUSCH resumption. In the depicted embodiment, intra-TTI hopping isdisabled and first and second UE 110 are paired for MU-MIMO PUSCHtransmission. The first UE 110 may be scheduled to transmit an sPUSCH 27in symbol S3 10, but cannot. In response to the resumption policy 217being satisfied, the PUSCH 21 a may resume at symbol S5 10 of slot 0 11.

FIG. 3D is a schematic diagram illustrating one alternate embodiment ofPUSCH resumption. In the depicted embodiment, intra-TTI hopping isdisabled and first and second UE 110 are paired for MU-MIMO PUSCHtransmission. The first UE 110 may be scheduled to transmit an sPUSCH 27in symbol S3 10, but cannot. The PUSCH 21 a may resume at symbol S7 10of slot 1 11.

FIG. 4 is a schematic block diagram illustrating one embodiment of UE110. In the depicted embodiment, the UE 110 includes a processor 405, amemory 410, and communication hardware 415. The memory 410 may comprisea semiconductor storage device. The memory 410 may store code. Theprocessor 405 may execute the code. The communication hardware 415 maycomprise a transceiver and may communicate with the eNB 105.

FIGS. 5A-B are a schematic flow chart diagram illustrating oneembodiment of a TTI resumption method 500. The method 500 may resume aTTI 16 such as a PUSCH 21 after a collision. The method 500 may beperformed by the processor 405.

The method 500 starts, and in one embodiment, the processor 405 detects505 a collision in slot 0 11. The collision may be between collisionbetween UE uplink transmission resources in a first TTI 16 of a firstTTI length and uplink transmission resources in a second TTI 16 of asecond TTI length. In a certain embodiment, the collision is between aPUSCH 21 and any sTTI 15 such as an sPUSCH 27.

The processor 405 may determine 510 if intra-TTI hopping is enabled. Inone embodiment, the processor 405 consults the intra-TTI hopping value201.

If intra-TTI hopping is enabled, the processor 405 may determine 515 ifthe first TTI 16 collided with the sTTI 15 in slot 0 11. If the firstTTI 16 collided with the sTTI 15, the processor 405 may resume 520 theTB in slot 1 11 such as is shown in FIG. 3A and the method 500 ends. Ifthe PUSCH DMRS 23 does not collide with the sTTI 15, the processor 405may resume 525 the TB in slot 0 11 such as is shown in FIG. 3B and themethod 500 ends.

If intra-TTI hopping is not enabled, in FIG. 5B, the processor 405determines 540 if the resumption policy 217 is satisfied. If theresumption policy 217 is satisfied, the first TTI transmission isresumed 545 in slot 0 11 as shown in FIG. 3C. If the resumption policy217 is not satisfied, the first TTI transmission is resumed 550 in slot1 11 as shown in FIG. 3D.

FIG. 5C is a schematic flow chart diagram illustrating one embodiment ofa TTI overlap method 600. The method 600 may resume a TTI transmissionwhen portions of TTI 16 such as a PUSCH 21 and an sPUSCH 27 overlap. Themethod 600 may be performed by the processor 405.

The method 600 starts, and in one embodiment, the processor 405 detects605 an overlap of portions of TTI such as a PUSCH 21 and an sPUSCH 27,such as is illustrated in FIG. 1E. As a result, some PUSCH UCI are nottransmitted as part of the PUSCH 21. The processor 405 may transmit UCIfrom the PUSCH 21 in the sPUSCH 27.

The processor 405 may calculate 610 the resource elements 12 fortransmitting the UCI from the PUSCH 21 in the sPUSCH 27. The number ofresource elements 203 for transmitting uplink control information (UCI)in the sPUSCH may be based on one or more of a number of previouslytransmitted UCI bearing single-carrier frequency division multipleaccess (SC-FDMA) symbols, an sTTI index with the subframe, and whetherthe PUSCH transmission is resumed after sTTI transmission within thesubframe.

In one embodiment, the number of resource elements 12 for transmittingrank indicators RI 31 is calculated using Equation 7, wherein O is anumber of RI 31, M_(SC) ^(PI) is specified by an initial PUSCH, N_(SC)^(PI) is a number of single carrier frequency-division multiple accesssymbols 10, β_(SC) ^(p) is an offset for the RI 31, and M_(SC) ^(P) is anumber of subcarriers 14 scheduled for the PUSCH, and wherein the numberof resource elements 12 for transmitting acknowledge/non-acknowledge AN33 is calculated using Equation 8, wherein O is a number of AN 33,M_(SC) ^(PI) is specified by an initial PUSCH, N_(SC) ^(PI) is a numberof single carrier frequency-division multiple access symbols 10, β_(SC)^(p) is an offset for the AN 33, and M_(SC) ^(P) is a number ofsubcarriers 14 scheduled for the PUSCH 21.

$\begin{matrix}{{QRI} = \left( {\left\lbrack \frac{\left. {{OM}_{SC}^{PI}N_{SC}^{PI}\beta_{SC}^{P}} \right\rbrack}{\sum\limits_{r = 0}^{C - 1}K_{r}} \right\rbrack 4M_{SC}^{P}} \right)} & {{Equation}\mspace{14mu} 7} \\{{QAN} = \left( {\left\lbrack \frac{{OM}_{SC}^{PI}N_{SC}^{PI}\beta_{SC}^{P}}{\sum\limits_{r = 0}^{C - 1}K_{r}} \right\rbrack 4\; M_{SC}^{P}} \right)} & {{Equation}\mspace{14mu} 8}\end{matrix}$

FIG. 5D is a schematic flow chart diagram illustrating one embodiment ofa resumption method 700. The method 700 may resume transmission of afirst uplink data TB. The method 700 may be performed by a processor405.

The method 700 starts, and in one embodiment, the processor 405 maydetermine 701 a collision between UE uplink transmission resources in afirst TTI 16 of a first TTI length and uplink transmission resources ina second TTI 16 of a second TTI length. The processor 405 may transmit703 a first uplink data TB in the first TTI 16. The processor 405 mayfurther transmit 705 a second uplink data TB in the second TTI 16.

The processor 405 may interrupt 707 the transmission of the first uplinkdata TB before transmission of the second uplink data TB. The processor405 may receive 709 an indication indicating whether to resumetransmission of the first uplink data TB after the transmission of thesecond uplink TB. In one embodiment, the indication is received viahigher layer than physical layer signaling such as RRC.

The processor 405 may determine 711 to resume or not to resume thetransmission of the first uplink TB based on the indication. In oneembodiment, the processor determines 711 to resume 713 transmission ofthe first uplink data TB if the UE 110 has determined to resume thetransmission of the first uplink TB, wherein the first TTI length islarger than the second TTI length, the first and the second TTI overlapat least in one symbol, the first TTI starts earlier than the secondTTI. If the processor 405 determines 711 not resume 713 transmission,the method 700 ends.

FIG. 5E is a schematic flow chart diagram illustrating one alternateembodiment of a resumption method 800. The method 800 may resumetransmission of a first uplink data TB. The method 800 may be performedas part of the method 700 of FIG. 5D. The method 800 may be performed bya processor 405.

The method 800 starts, and in one embodiment, the processor 405 receives801 a second indication indicating an intra-TTI resource hoppingcorresponding to uplink data transmissions of the first TTI length.

The processor 405 may determine 803 if the second uplink data TB in thesecond TTI 16 overlaps in time with DMRS 23 associated with the firstuplink data TB in the first TTI 16.

The processor 405 may determine 805 if the intra-TTI resource hopping.The processor 405 may determine 805 if the intra-TTI resource hopping isset based on the indication. If the intra-TTI resource hopping is setbased on the indication, an uplink data transmission associated with aTTI 16 of the first TTI length is performed in at least a first set anda second set of resources, wherein at least the second set is determinedat least based on the first set. The uplink data transmission may beperformed in the first set of resources in a first portion of the TTI 16and in the second set of resources in a second portion of the TTI 16.The first portion and the second portion may not overlap in time. If theintra-TTI resource hopping is not set based on the indication, an uplinkdata transmission associated with a TTI 16 of the first TTI length isperformed only in the first set of resources over the TTI duration.

In one embodiment, the processor determines 803 whether to resume 805 ornot to resume the transmission of the first uplink TB based on the firstindication and one or more of the second indication, a transmission rankassociated with the first uplink data TB and determination of overlapbetween the DMRS 23 associated with the first uplink data TB and thesecond uplink data TB, wherein the transmission rank associated with thefirst uplink data TB is a number of transmission layers or a number ofdata streams associated with the first uplink data transmission in thefirst TTI.

The processor 405 may determine 805 not to resume the transmission ofthe first uplink TB in the first TTI block if the DMRS 23 of the firstuplink data TB in a slot 1 11 of the first TTI 16 overlapped with thesecond uplink TB and the second TTI 16 is a subset of slot 0 11 of thefirst TTI 16.

If the processor 405 determines 803 not to resume the first uplink TBtransmission, the method 800 ends. If the processor 405 determines 803to resume the first uplink TB transmission, the processor 405 may resumetransmission in one or slot 0 11 and slot 1 11. Transmission may beresumed 807 in slot 1 11 if the DMRS 23 of the first uplink data TB in afirst slot of the first TTI 23 overlapped with the second uplink TB. Inone embodiment, the first TTI 16 is the union of slot 0 11 and slot 111. The second TTI 16 may be a subset of slot 0 11 of the first TTI 16.The slot 0 11 and slot 1 11 of the first TTI 16 may not overlap.

In one embodiment, for transmission ranks lower than a threshold, thetransmission of the first uplink TB is not resumed. The first uplinkdata TB may contain feedback information. The feedback information mayinclude at least one of A/N 33 in response to downlink transmissions ortransmission RI 31. A portion of the feedback information may beincluded in the second uplink data TB.

In one embodiment, the number of resources required for transmission ofthe feedback information in the second TTI is determined based on atleast one of: the number of transmitted feedback information in thefirst TTI 16 before interrupting the transmission of the first uplinkdata TB; the location of the second TTI 16 within the first TTI 16; andthe determination of whether to resume or not to resume the transmissionof the first uplink TB.

In one embodiment, the first uplink data TB is transmitted with atransmission power determined at least based on a transmission powercontrol command (TPC) or a power control adjustment state associatedwith the transmission power of a third uplink transmission in a TTI 16of the second TTI length. The TPC command may indicate an adjustment totransmission power of the third uplink transmission in a TTI 16 of thesecond TTI length.

The power control adjustment state indicates and/or includes a historyof transmission power adjustments corresponding to transmissions priorto the transmission of the third uplink transmission. The power controladjustment state indicates and/or includes a history of transmissionpower adjustments corresponding to transmissions prior to thetransmission of the third uplink transmission. The third uplinktransmission may be performed before the transmission of the firstuplink transmission data block. Transmission power corresponding to thesecond uplink transmission data block may be determined at least basedon the transmission power corresponding to an uplink transmission in aTTI 16 of the second TTI length.

INDUSTRIAL APPLICABILITY

UE uplink transmission resources in a first TTI 16 of a first TTI lengthmay collide with an uplink transmission resources in a second TTI 16 ofa second TTI length. The embodiments determine whether to resumetransmission of the first TTI 16, and if transmission of the first TTI16 is resumed, latency is reduced.

Embodiments may be practiced in other specific forms. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

The invention claimed is:
 1. A method at a device, comprisingdetermining, by use of a processor, a collision between user equipment(UE) uplink transmission resources in a first TTI of a first TTI lengthand uplink transmission resources in a second TTI of a second TTIlength; transmitting a first uplink data transmission block (TB) in thefirst TTI; transmitting a second uplink data TB in the second TTI;interrupting the transmission of the first uplink data TB beforetransmission of the second uplink data TB; receiving an indicationindicating whether to resume transmission of the first uplink data TBafter the transmission of the second uplink TB; determining to resume ornot to resume the transmission of the first uplink TB based on theindication; and resuming the transmission of the first uplink TB in thefirst TTI block after the transmission of the second uplink TB if the UEhas determined to resume the transmission of the first uplink TB,wherein the first TTI length is larger than the second TTI length, thefirst and the second TTI overlap at least in one symbol, the first TTIstarts earlier than the second TTI; receiving a second indication,indicating an intra-TTI resource hopping corresponding to uplink datatransmissions of the first TTI length, wherein if the intra-TTI resourcehopping is set based on the indication, an uplink data transmissionassociated with a TTI of the first TTI length is performed in at least afirst set and a second set of resources, wherein at least the second setis determined at least based on the first set, and wherein the uplinkdata transmission is performed in the first set of resources in a firstportion of the TTI and in the second set of resources in a secondportion of the TTI; and wherein the first portion and the second portiondo not overlap in time, and if the intra-TTI resource hopping is not setbased on the indication, an uplink data transmission associated with aTTI of the first TTI length is performed in the first set of resourcesover the TTI duration.
 2. The method of claim 1, wherein the indicationis received via higher layer than physical layer signaling.
 3. Themethod of claim 1, further comprising: receiving the second indication,indicating that the intra-TTI resource hopping is set; determining ifthe second uplink data TB in the second TTI overlaps in time withdemodulation reference signals (DMRS) associated with the first uplinkdata TB in the first TTI; and determining to resume or not to resume thetransmission of the first uplink TB based on the first indication andone or more of the second indication, a transmission rank associatedwith the first uplink data TB and determination of overlap between theDMRS associated with the first uplink data TB and the second uplink dataTB, wherein the transmission rank associated with the first uplink dataTB is a number of transmission layers or a number of data streamsassociated with the first uplink data transmission in the first TTI. 4.The method of claim 3, wherein resuming the transmission of the firstuplink TB in the first TTI block further comprises resuming thetransmission of the first uplink TB in a second slot of the first TTIblock if: the DMRS of the first uplink data TB in a first slot of thefirst TTI overlapped with the second uplink TB; and the second TTI is asubset of the first slot of the first TTI, wherein the first slot andthe second slot of the first TTI do not overlap.
 5. The method of claim4, wherein the first TTI is the union of the first and the second slots.6. The method of claim 3, wherein the transmission of the first uplinkTB in the first TTI block is not resumed if: the DMRS of the firstuplink data TB in a second slot of the first TTI overlapped with thesecond uplink TB; and the second TTI is a subset of the first slot ofthe first TTI, wherein the first slot and the second slot of the firstTTI do not overlap.
 7. The method of claim 3, wherein for transmissionranks lower than a threshold, the transmission of the first uplink TB isnot resumed.
 8. The method of claim 1, wherein the first uplink data TBcontains feedback information.
 9. The method of claim 8, wherein thefeedback information includes at least one of acknowledgment (ACK/NACK)in response to downlink transmissions or transmission rank indicator(RI).
 10. The method of claim 9, wherein a portion of the feedbackinformation is included in the second uplink data TB.
 11. The method ofclaim 10, wherein the number of resources required for transmission ofthe feedback information in the second TTI is determined based on atleast one of: the number of transmitted feedback information in thefirst TTI before interrupting the transmission of the first uplink dataTB; the location of the second TTI within the first TTI; and thedetermination of resume or not to resume the transmission of the firstuplink TB.
 12. The method of claim 11, wherein the number of transmittedfeedback information in the first TTI before interrupting thetransmission of the first uplink data TB is the number of symbols intime containing the feedback information.
 13. The method of claim 1,wherein the first uplink transmission data block is transmitted with atransmission power determined at least based on a transmission powercontrol command (TPC) or a power control adjustment state associatedwith the transmission power of a third uplink transmission in a TTI ofthe second TTI length, wherein: the TPC command indicates an adjustmentto transmission power of the third uplink transmission in a TTI of thesecond TTI length; the power control adjustment state indicates ahistory of transmission power adjustments corresponding to transmissionsprior to the transmission of the third uplink transmission; and Thethird uplink transmission is performed before the transmission of thefirst uplink transmission data block.
 14. The method of claim 1, whereintransmission power corresponding to the second uplink transmission datablock is determined at least based on the transmission powercorresponding to an uplink transmission in a TTI of the second TTIlength.
 15. An apparatus comprising: a processor performing: determininga collision between user equipment (UE) uplink transmission resources ina first TTI of a first TTI length and uplink transmission resources in asecond TTI of a second TTI length; transmitting a first uplink datatransmission block (TB) in the first TTI; transmitting a second uplinkdata TB in the second TTI; interrupting the transmission of the firstuplink data TB before transmission of the second uplink data TB;receiving an indication indicating whether to resume transmission of thefirst uplink data TB after the transmission of the second uplink TB;determining to resume or not to resume the transmission of the firstuplink TB based on the indication; and resuming the transmission of thefirst uplink TB in the first TTI block after the transmission of thesecond uplink TB if the UE has determined to resume the transmission ofthe first uplink TB, wherein the first TTI length is larger than thesecond TTI length, the first and the second TTI overlap at least in onesymbol, the first TTI starts earlier than the second TTI; receiving asecond indication, indicating an intra-TTI resource hoppingcorresponding to uplink data transmissions of the first TTI length,wherein if the intra-TTI resource hopping is set based on theindication, an uplink data transmission associated with a TTI of thefirst length is performed in at least a first set and a second set ofresources, wherein at least the second set is determined at least basedon the first set, and wherein the uplink data transmission is performedin the first set of resources in a first portion of the TTI and in thesecond set of resources in a second portion of the TTI; and wherein thefirst portion and the second portion do not overlap in time, and if theintra-TTI resource hopping is not set based on the indication, an uplinkdata transmission associated with a TTI of the first TTI length isperformed in the first set of resources over the TTI duration.
 16. Theapparatus of claim 15, wherein the indication is received via higherlayer than physical layer signaling.
 17. The apparatus of claim 15, theprocessor further: receiving the second indication, indicating that theintra-TTI resource hopping is set; determining if the second uplink dataTB in the second TTI overlaps in time with demodulation referencesignals (DMRS) associated with the first uplink data TB in the firstTTI; and determining to resume or not to resume the transmission of thefirst uplink TB based on the first indication and one or more of thesecond indication, a transmission rank associated with the first uplinkdata TB and determination of overlap between the DMRS associated withthe first uplink data TB and the second uplink data TB, wherein thetransmission rank associated with the first uplink data TB is a numberof transmission layers or a number of data streams associated with thefirst uplink data transmission in the first TTI.
 18. The apparatus ofclaim 17, wherein resuming the transmission of the first uplink TB inthe first TTI block further comprises resuming the transmission of thefirst uplink TB in a second slot of the first TTI block if: the DMRS ofthe first uplink data TB in a first slot of the first TTI overlappedwith the second uplink TB; and the second TTI is a subset of the firstslot of the first TTI, wherein the first slot and the second slot of thefirst TTI do not overlap.
 19. The apparatus of claim 18, wherein thefirst TTI is the union of the first and the second slots.
 20. Theapparatus of claim 17, wherein the transmission of the first uplink TBin the first TTI block is not resumed if: the DMRS of the first uplinkdata TB in a second slot of the first TTI overlapped with the seconduplink TB; and the second TTI is a subset of the first slot of the firstTTI, wherein the first slot and the second slot of the first TTI do notoverlap.